This disclosure relates generally to the field of medical devices, systems and methods for use in surgical procedures. More specifically, this disclosure relates to electrosurgical devices, systems and methods that provide for cutting, coagulation, hemostasis, or sealing of bodily tissues including bone with an electrosurgical device.
Electrosurgery includes such techniques as cutting, coagulation, hemostasis, and/or sealing of tissues with the aid of electrodes energized with a suitable power source. Typical electrosurgical devices apply an electrical potential difference or signal between an active electrode and a return electrode on a patient's grounded body in a monopolar arrangement or between an active electrode and a return electrode on the device in bipolar arrangement to deliver electrical energy to the area where tissue is to be affected. The electrosurgical devices are typically held by the surgeon and connected to the power source, such as an electrosurgical unit having a power generator, via cabling.
Electrosurgical devices pass electrical energy through tissue between the electrodes to provide coagulation to control bleeding and hemostasis to seal tissue. Electrosurgical devices can also cut tissue through the use of plasma formed on the electrode. Tissue that contacts the plasma experiences a rapid vaporization of cellular fluid to produce a cutting effect. Typically, cutting and coagulation are often performed with electrodes in the monopolar arrangement while hemostasis is performed with electrodes in the bipolar arrangement.
Electrical signals can be applied to the electrodes either as a train of high frequency pulses or as a continuous signal typically in the radiofrequency (RF) range to perform the different techniques. The signals can include a variable set of parameters, such as power or voltage level, waveform parameters such as frequency, pulse duration, duty cycle, and other signal parameters that may be particularly apt or preferred for a given technique. For example, a surgeon could cut tissue using a first RF signal having a set of parameters to form plasma and control bleeding using a second RF signal having another set of parameters more preferred for coagulation. The surgeon could also use electrodes in a bipolar arrangement or a bipolar electrosurgical device for hemostatic sealing of the tissue that would employ additional RF signals having another set of parameters.
Historically, two distinct electrosurgical devices, one monopolar and the other bipolar, were used to perform different functions in surgery, such as tissue cutting and coagulating and tissue sealing. For example a surgeon would use a monopolar electrosurgical device to cut and coagulate tissue and use a bipolar electrosurgical device to seal the tissue. When different techniques or functions were performed during a surgical procedure, surgeons would switch between different devices. Switching between devices can lead to undesirable effects such as longer procedure times, longer response times to issues that unexpectedly develop during surgery, higher costs, and an increased likelihood of inaccuracy or imprecision.
To address these issues, some electrosurgical devices capable of performing multiple techniques such as cutting and coagulating tissue or cutting, coagulating, and sealing tissue, including fluid-assisted sealing of tissue, have been developed. Several such electrosurgical device are described, for example, in U.S. Pat. No. 8,632,533 to Greeley, et al., U.S. Patent Application Publication No. 2012/000465 to Conley, et al., U.S. Patent Application Publication No. 2011/0178515 to Bloom et al., each assigned to the assignee of the present disclosure and incorporated by reference herein in their entireties to the extent they are not inconsistent with the present disclosure.
Several devices that have been developed include a hand piece having two electrodes. These devices can be configured as bipolar electrodes connected to a source of bipolar power to operate in a bipolar mode, for example to seal tissue. To operate the same two-electrode device in a monopolar mode, for example to cut tissue, one of the two electrodes may be selectively deactivated and the other of the two electrodes coupled to a source of monopolar power. In this manner, the multiple function device may provide treatment to tissue utilizing one or both electrodes depending upon the desired tissue treatment.
Despite having the ability to perform different functions with a single device, when monopolar function is desired only one of the two electrodes of the device are utilized and the deactivated second electrode may obstruct the view of the surgeon during the monopolar operation. Furthermore, the deactivated electrode may unnecessarily prevent the monopolar electrode from entering smaller spaces or tissue areas that could otherwise be accessed if the unused electrode was not exposed. Further still, devices may not perform similarly to independent bipolar and monopolar devices.